Evangelista Torricelli


Every time you turn on the TV or radio and hear a weather forecast, one man
is responsible for the birth of meteorology, the science of predicting the
weather. His name is Evangelista Torricelli, an Italian scientist and
mathematician. In 1643, he invented perhaps one of the most important devices in
predicting weather: the barometer.

Evangelista Torricelli was born October 15th, 1608 in what is now known as
Faenza, Italy. Little information is known about his early years of life. In
1624 he entered the Jesuit College of Faenza, then moved on to the Collegio
Romano in Rome. Here his talents and intellect were recognized and he was then
moved on to the University of Sapienza, now known as the University of Rome, to
be taught by the great Italian professor, Castelli. Also during this time,
Torricelli served as Castelliís secretary from 1636 to 1642. Over the next
nine years he served a large number of professors as a secretary and learned
much from each of them.

Torricelli is included in our textbook for his two major contributions to the
world of science. First of all, he invented the barometer, a device that is
still used today to measure the amount of atmospheric pressure, which is helpful
for detecting inclement weather. Secondly, he is the namesake for a unit of
pressure known as the Torr. The invention of the barometer is considered by most
to be his biggest contribution to science. While serving as Galileoís
secretary from 1641 to 1642, he learned many things about pressure and
temperature from the great scientist. Galileo had been struggling to create a
water thermometer. He could not understand why water could not be suspended in a
tube taller than 34 feet. After much research, Torricelli discovered the answer:
air has weight. The water could not stay in the tube due to the incredible
amount of pressure being exerted on it by the air above. His invention of the
mercury filled barometer in 1643 proved this theory and also proved the
existence of air pressure.

In his lifetime, Torricelli had many great accomplishments and contributions
to the areas of science and mathematics. He was the first man to create a
sustained vacuum, which led to the discovery of the barometer. He proved that
the flow of liquid through an opening is proportional to the square root of the
height of the liquid, a theory that is now known as Torricelliís theorem. He
succeeded Galileo as the court mathematician to Grand Duke Ferdinando II of
Tuscany. He also found the length of the arc of a cycloid, which is the curve
that is traced by a point on the circumference of a rotating circle. In other
mathematical areas, he determined the point in the plane of a triangle where the
sum of its distances from the vertices is the smallest. This is also known as
the isogonic center. In 1644 he published a book about his studies in projectile
motion, entitled Opera Geometrica. Torricelli also had significant talents in
the grinding of lenses for telescopes and microscopes. He supported himself in
the final years of his life with these talents.

On the evening of October 25th, 1647, Evangelista Torricelli died at the
young age of 39 in the palace of Duke Ferdinando. He had fathered many important
discoveries in his short life. With the naming of the Torr. after him, along
with the moonís Crater Torricelli and Rue Torricelli, a street in Paris, he is
surely to never be forgotten by the scientific community or the rest of the

Category: Biographies